This invention relates generally to the field of control circuitry for appliances and more particularly to circuitry for powering up a microprocessor based appliance including an electromechanical switch located behind a membrane touch panel.
There has been shown in prior appliance panel switch mounting construction various switches which are manually operable for being set and latched in a contact closed or conductive posture. At a predetermined time in a cycle of operations these switches are electrically reset or returned to a contact open or nonconductive posture. Zane, U.S. Pat. No. 3,673,531, is an example of a multi-button switch mechanism generally used in the control panel of a dishwasher. At least one of the several switches in this mechanism is manually set to a closed posture and at a predetermined time in the dishwasher cycle of operations a bimetallic heating element is actuated through the timer to release the switch allowing it to return to its open posture.
Keuleman et al in U.S. Pat. No. 4,209,915, also teaches a mechanical push button switch for initiating a cycle of events. A holding capacitor is charged and is eventually discharged through a transistor circuit which is turned on by a controller for terminating operations. A relay operates to hold the switch contact in the closed posture until the operations are terminated.
While the above constructions disclose manually-set electrically-reset switch mechanisms it is desirable in an appliance having a touch membrane type switch to provide a completely smooth control panel surface. This desirable feature has not been shown in the prior art in conjunction with a manually-set electrically-reset start switch mounted behind a smooth flexible control panel surface and operable by depressing the smooth flexible membrane surface of the control panel. There is thus provided herein a manually-set electrically-reset switch operable for powering-up a microprocessor control circuit while maintaining the smooth unbroken surface appearance of a flexible membrane control panel surface.